Telegraph transmitter



ntedi Sa TELEGRAPH TRANSMITTER Gordon Sim, Chicago, Ill., assignor to Teletype Corporation, Chicago, Ill., a corporation of Delaware This invention pertains to telegraph transmitters and more particularly to improvements in cam type transmitters.

The primary object of the invention is to provide facilities for insuring the accurate and stable operation of the transmitter contacts.

Another object of the invention is to provide means for stabilizing the operation of transmitting contacts to thereby eliminate bounce in the selective actuation of said contacts.

Specifically, the arrangement according to the present invention provides in a transmitter having a signal generator comprising a rocker member actuated through the instrumentality of specially conformed interponents by a series of sequentially operable cams, a contact stabilizing device adapted to eliminate bounce and control the rocking action of the rocker arm of the transfer mechanism. The stabilizing device according to the invention comprises a pair of confronting spring loaded elements alternately presentable in blocking or latching relationship with said rocker member.

A better understanding of the invention may be had from the following description, taken in conjunction with the accompanying drawings, wherein:

Fig. l is an elevational view of the signal generator embodying the present invention, and

Fig. 2 is a view representing an alternate condition of operation of the device shown in Fig. l.

In the embodiment shown, the details of the telegraph transmitter which cooperate with the device according to the present invention, but which do not constitute a part of the combination comprising the invention, have not been shown in the drawing and will not be described herein since they are shown and described in United States Patent No. 2,607,848 granted August 19, 1952, to W. I. Zenner, which disclosure is incorporated herein by reference, and made a part hereof. v

Briefly, the apparatus embodying the device according to the present invention embraces primarily a base por-` tion which is provided at its forward portion with a keyboard (not shown) of usual form, and which is adapted to house the key levers 11, shown in section in Fig. l, and the selector mechanism operated thereby, exemplified by the code bars 12. Mounted on the base are the signal generator 13 and related parts which are selectively controlled by the aforementioned selector mechanism of which code bars 12 are a part. A motor (not shown) `for supplying the power for operating the keyboard transmitter is appropriately mounted on the base portion in position to effect the rotation of the operating shaft 14. The cyclic rotation of the transmitting cams 15 carried on shaft 14 is governed by a single revolution clutch, as set forth in the aforementioned patent.

Having reference to Fig. 1, the key levers 11 control the setting of code bars 12 permutably. As set forth in said patent, the code bars 12 are normally biased rightwardly by individual springs (not shown), but are held in their leftward position by a bail member (similar arent 1, 2,795,646 Patented June 11, 1957 `tion type, and is normally locked against rotation by a release lever (not shown) controlled by a universal bar 16 upon the actuation of a key lever 11. According to the present invention, each of the code bars 12 is provided with a vertically projecting portion 17, the upper end of which is adapted to cooperate with a projection 18 of a specially conformed interponent member 19. Interponents 19 are mounted on a common rod 21 appropriately located below the shaft 14, and are provided with individual cam follower portions 22 adapted to cooperate withrtheir respective transmitting cams 15. Interponents 19 are normally biased upwardly and counterclockwise simultaneously by individual springs 23, said interponents being slotted at 24 to permit vertically reciprocating movement thereof by cams 15. Cams 15 are helically arranged around shaft 14 to effect the reciprocation of interponents 19 sequentially, in a manner well known in the art.

Each of the interponents 1.9 is provided at its upper end with a pair of arms 25 and 26, having inwardly directed and confronting abutting portions 27 and 28, respectively, adapted to overhang a corresponding pair `of abutments 29 and 31 of a rocker or oscillatable member 32 supported pivotally on a pivot rod 33. Thus, when the code bar 12 is actuated rightwardly in response to a marking condition, its projection 17 will actuate interponent 19 in a clockwise direction to present abutment 27 over the abutment 29 of the rocker member 32. Then when the interponent 19 is depressed by its cam 15 the rocker member 32 will be rotated to its counterclockwise position, Fig. 2.

Cooperating with the upper extension or latchable portion 34-of rocker member 32, on opposite edges thereof, are a pair of stabilizing elements or retainer instrumentalities 35 and 36. Retainers 35 and 36 are supported pivotally on studs 37 and 38, respectively, and are normally attrahently biased; that is, toward each other, and toward the extension 34 by a common spring 39. Spring 39 simultaneously functions to impart clockwise bias to retainer 35 thereby tending to bring the tail portion 41 into engagement with a camming out stud 42, as will presently appear. Similarly, spring 39 also functions Aat the same time to bring tail portion 43 of retainer 36 into engagement with a camming out stud 44. Retainers 35 and 36 are provided with slotted holes 45 to permit slidableas well as pivotal motion on their respective studs 37 and 38.

The rocker member 32 functions through a link 46 to control the transmitting contact assembly contained in the housing 47. Link 46 is articulated to the rocker 32 in such a manner that the knife edge extremity 48 of link 46 is caused to bear normally in a V-shaped groove 49 by means of a spring 51 distended between the opening 52 in rocker member 32 and a lug 53 on link 46.

The right-hand end of link 46 (as viewed in Fig. 1) is articulated to the operating lever 54 of the contact assembly by engaging a notch 55 therein. Operating lever 54 is connected pivotally to the stem of a T-shaped lever 56. Each of the arms of the T-lever 56 is pro- At a point centrally located between a substantially U-shaped member 62, the other arm of which cooperates with a V-shaped notch 63 in a bracket 64 mounted in the housing 47. A spring 65 having one end attached to the member 62 has the other end attached to a spring post 66.

The spring 65 is thus so connected that the member 62 will be urged normally in a clockwise direction V(Fig. 1) urging the contact points 57 toward their associated contact points 58. With the notch 61 centrally located, a balanced pressure is exerted with respect to both of the contact points 57. In actual practice the operating lever 56 will normally beheld in such a position that only one contact pair 57-58 will be closed at a time. Thus, the operating lever 56 will be in one of its two positions, or moving from one to theother, which causes the T-lever 56 to be positioned in such a manner as to cause one of the contact points 57 to fulcrum about its associated contact point 57. As a change ofuselectionis made in the operating lever 54, under the control of the rocker member 32, aswill presently appear, the T-lever 56 will be moved from one position to the other, and as the lever 56 is not pivoted about an external point, it will fulcrum about the contact pair which is desired to be closed.

Also slidably mounted on rod 21 is a detent member 67 which is guided at its upper end by a stud 68 adapted to cooperate slidably with the open ended slot 69. Detent 67 is urged in an upward direction by aV spring 71 to normally coact with a cam 72 carried on the shaft 14. Detent member 67 is provided with a knife edge 73 adapted to cooperate with individual knife edges 74 depending from the several interponents 19. Interponents 19 are also provided with stop portions 75 and 76 adapted to cooperate with the knife edge 73 to limit the clockwise and counterclockwise movements of the respective `interponents 19.

The timingV of cam 72 is such that when the code bars 12 are positioned permutably pursuant to the actuation of a key lever 11, the interponents 19 will bey correspondingly positioned in their clockwise and counterclockwise positions to cause stops 75 and 76, respectively, to bear against the knife edge 73, so that during the early part of the cycle of rotation of shaft 14, and hence cam 72, the detent member 67 will be permitted to rise due to the pull of spring 71, to bring the knife edge 73 to its upper position, with depending knife edges 74 disposed on the right or left side of knife edge 73, depending upon the permuted setting of interponents 19. The interponents 19 will therefore be locked against rightward or leftward movement by having the knife edge 73 positioned either between a stop 75 and a knife edge 74, or between a stop 76 or a knife edge 714. The interponents 19 are not, however, locked against 'vertical movement under the control of cams 15.

In the operation of the arrangement according to the present invention, the stabilizing elements or instrumentalities 35 and 36 are eiectivepursuant to each oscillation of the rocker member 32 to preclude contact bounce by preventing chatter or bounce between the abutments 27 and 29, or between abutments 28 and 3.1. The code bars 12 are positioned permutably in response to the initiation of key lever 11, through projections 17, to thereby correspondingly position the interponents 19 in their rightward (clockwise) or leftward (counterclock- Y65 bars 12 are returned to their leftward position, the .cam

wise) positions. The timing is such that before the code 72 will have rotated suticiently to permit the detent 67 to rise to cause the knife edge 73 to cooperate with the right or left side of depending knife edge 74.

While the interponents 19 are thus constrained, the helically arranged cams function to sequentially depress said interponents 19. If an abutment `27 is positioned over the abutment 29, then the rocker member 32 will be rocked in a counterclockwise direction to assume the position shown in Fig. 2. Conversely, an

v counterclockwise.

plies a steadying force to said member 32. Now, as-

suming that the interponents 19 are constrained for vertical reciprocation, as previouslyV described, and the interponent 19 is in marking position; that is, with its abutment 27 presented over the abutment 29, then under the control of its associated cam 1S the interponent 19 is depressed thereby causing the member 32 to rotate In thus rotating, the member 32 through its upper extension 34 urges the retainer or instrumentality 35 leftwardly under the constant tension of spring 39. At the same time, the cam-ming surface 77 of retainer 35 coacts with the stud 42 to cause said retainer 35 to rotate in a counterclockwise direction, thus eventually stripping the latched end 78 from the extension 34. By the time this will have occured, the confronting edge 79 of the companion retainer 36 will have dropped behind the opposite (or right) side of extension 34 causing the rocker member 32 to be maintained in its counterclockwise position, as shown in Fig. 2, thereby preventing chatter or bounce of both the member 32 and contacts 64-65.

, Conversely, if the member 32 is found in its counterclockwise position when a code bar 15 is in its leftward or spacing position, then the abutment 28 will be presented over the abutment 31 and when the interponent 19 is depressed by its cam 15 the rocker member 32 will be swung to its clockwise position, thereby urging the retainer 36 rightwardly. The camming action between cam surface 79 of retainer 36 and the stud 44 will cause the retainer 36 to gradually become unlatched as it is moved n'ghwardly until finally retainer 35 will cooperate with the extension 34 to maintain the rocker member 32 in its clockwise position shown in Fig. l.

Although a preferred form of the invention has been disclosed and described, it is obvious that changes may be made in the details set forth Without departing from the essentials of the invention` What is claimed is:

1. In a'transmitter, a Isignal generator comprising a rocker member, a .series of sequentially operable cams, an interp-onent associated with each cam, said interponent having elements operably disposed Awith respect to sai-d rocker member, means for setting said interponenits in accordance with a predetermined code, means for operating said cams to -actuate said interp-onents sequentially, transmitting contact means, means controlled by said rocker member for controlling the actuation of said .transmitting contact means, and means for stabilizing said contact means comprising a pair of confnonting spring loaded elements alternately presentable 'in butting relation-ship with said rocker member.

2. In a transmitter, Ia signal generator comprising a rocker member, a yseries of sequentially operable cams, Ian interponent .associated with each cam, said interponent having elements operably disposed with respect to said rockermember, means for set-ting said interponents in accordance with .a predetermined code, means for operating said cams to actuate said yinterponents sequentially, mansmitting contact means, means `controlled by said rocker member for controlling the actuation `of said transmitting contact means, and means for 'stabilizing said -c-ontact means comprising a pair of spring loaded elements having confronting edges cooperable with said rocker member, whereby upon the oscilla-tion of said rocker member during the sequential .actuation .of vsaid inter- .ponents said spring loaded elements are alternately presentable in butting relationship with said rocker member.

3. In a transmitter, a signal generator comprising a rocker member, a series of sequentially operable cams, an interponent associated with each cam, said interponent having elements operably disposed with respect Ito said rocker member, means -for setting said interponents in accordance with a predetermined code, means `for operating said calm-s to actuate said interponents sequentially, transmitting contact means, means controlled by said rocker member for controlling :the actuation of said transmitting contact means, and means tor stabilizing said contact means comprising a pair of a attrahently biased elements having confronting edges cooperable with said rocker member, whereby upon the oscillation of said rocker member during the sequential actuation -of said interp-onents said sattrahently biased elements are .alternately present-able in bwtting relationship with said .rocker member.

4. In a transmitter, a signal `generator comprising a rocker member, a series lof sequentially operable cams, an initerponent associated with each cam, said interponent having elements operably disposed with respect to said rocker member, means for setting said interponents in accordance with a predetermined code, means for operating said cams to actua-te said interponents sequentially, transmitting lcontact means, means controlled by said rocker member for controlling the actuation of said transmitting contact means, and means for stabilizing said contact means comprising a pair of attrahently biased instrumentalities which are pivotally :and slidably mounted, cam means associated with each of said instrumentalities, said instrumentalities having confronting edges cooperable with said rocker member, whereby in response -t-o .the conjoint action of said cam means and sa'id rocker member said inst-rumentalities are alternately presentable in butting relationship with said rocker member.

l5. In a transmitter, sa signal .generator comprising an oscillata'ble member having a latchable portion, .a series of sequentially operable cams, an interponent associated with eac-h cam, said interponent having elements operably disposed with respect to said member, means for setting said interponents in accordance with .a predetermined code, means for operating said cams to iactuate said interponents sequentially, transmitting contact means, means controlled by said member for controlling the actuation of said :transmitting conltact means, and means lfor stabilizng said contact means comprising a pair of attrahently biased instrlnnentalities, cam means associated with each of said instrumentalities, said instrumentalities having confronting edges cooper-able with said latchable portion, whereby in response to the conjoint action of sai-d cam means and said latchable portion said instrumentalities are alternately presentable in butting relationship with said member.

References Cited in the le of this patent UNITED STATES PATENTS 2,274,911 Spencer Mar. 3, 1942 

